Aortic endothelial and smooth muscle cell interactions in culture.

The effect of conditioned media on cell growth was studied in pig aortic smooth muscle cell conditioned medium on pig or bovine aortic endothelial cells and pig or bovine endothelial cells conditioned medium on pig aortic smooth muscle cell proliferation. Co-culturing experiments were also done in the same combinations. Cell proliferation was measured in both systems by 3H-thymidine incorporation autoradiography. In intraspecies combinations the media conditioned by confluent pig-aortic endothelial monolayer had an inhibitory effect on pig-aortic smooth muscle cell growth, but in the co-cultivation system the exponentially grown endothelial cells stimulated smooth muscle cell proliferation. The pig aortic smooth muscle cells had some stimulatory effect on pig endothelial cell proliferation in both systems. In the interspecies combination the media conditioned by confluent bovine aortic endothelial monolayer or, in the co-cultivation experiments, the bovine endothelial cells exerted a stimulatory effect on the proliferation of pig-aortic smooth muscle cells. The media conditioned by pig smooth muscle cells had also some little stimulatory effect on bovine aortic endothelial cell growth, but in the co-cultivation system the bovine aortic endothelial cells responded in a highly sensitive way to the stimulatory effect of pig aortic smooth muscle cells.